It is common practice for persons in construction, building, and maintenance trades to use work platforms and scaffolding to access elevated work areas. The safety and productivity of workers using these portable work platforms or scaffolds requires that the platforms or scaffolds be physically stable, be easy to position, be substantially level, and be readily moved from place to place.
The majority of portable work platforms or scaffolds currently in use in the construction and maintenance trades are supported by four legs or points of contact with the ground (i.e., support elements). In some instances, these legs are to be fitted with stem casters to facilitate relocation between workplaces.
The ground or floor surface at many construction sites and other work locations is often irregular and uneven. In current field practice, significant time and effort may be required to level the scaffolding by placing wooden blocks or other cribbage under the platform support legs, wheels, or casters. It is common for many portable scaffolds, such as those fitted with wheels, to be inadequately blocked or leveled due to the unavailability of proper cribbage and/or hasty installation.
Often the best points of support (i.e., solid, level surfaces) for a work platform do not correspond with the location of the work platforms vertical support elements. This requires the users to either move the platform to a less than ideal location to perform the overhead task, or tolerate an unstable (and often unsafe) work platform.
It is common practice for existing scaffolding to be constructed from tubular structural members. However, the geometry of traditional tubular scaffolding members provide high load bearing capacities, but do not provide torsional rigidity. As a result, traditional scaffolding must be fitted with diagonal braces. However, diagonal braces often interfere with tasks such as painting, tuck pointing or other maintenance or construction activities.
In many applications the use of scaffolding or work platforms could enable workers to perform their tasks more efficiently and safely than is possible working from an extension or step ladder. However, the use of scaffolding may be limited because, in most application, traditional scaffolding is too large or cumbersome to fit through a narrow door way or similar obstruction. As such, valuable work time is often wasted ascending, descending, and/or repositioning ladders.